1. Field of the Invention
The present invention relates to a portable device equipped with a plurality of module units having non-contact short-range communication capability in which the module units respectively perform functions by means of performing authentication processing through non-contact short range communication, thereby fulfilling one function as a whole and, more particularly, a technique for feeding power to the module units to perform authentication processing.
2. Description of the Related Art
FIG. 14 shows a block diagram showing a portable device having a plurality of modules. The “module units” are hereunder described simply as “modules.” A portable device 10 shown in FIG. 14 includes an application processing module 11, an input module 12, an acoustic module 13, a communication module 14, and a display module 15.
The application processing module 11 has an application processing function unit (an individual function unit) 111 for performing processing in order to carry out various application functions of the portable device 10. The input module 12 has an input processing function unit (an individual function unit) 112 including an input device, like a keyboard and a touchpad. The acoustic module 13 includes a speaker 113a, a microphone 113b, and an acoustic function unit (an individual function unit) 113 that performs audio input/output processing and control of the speaker and the microphone. The communication module 14 has a communication function unit (an individual function unit) 114 including a base band circuit, an RF (Radio Frequency) processing circuit, and the like. The display module 15 has a display unit (an individual function unit) 115 including a display unit using liquid crystal, organic EL, and the like, and a display control circuit that controls activation of the display unit. In addition to the respective individual function units 111 to 115, the respective modules 11 to 15 are equipped with short range communication units 12a to 12e for establishing short range communication with the other modules in a non-contacting manner and batteries 11a to 11e that feed electric power to respective units in the respective modules.
The portable device 10 shown in FIG. 14 performs authentication processing among the modules 11 to 15 through non-contact short range communication as pre-processing for letting the individual function units 111 to 115 of the respective modules 11 to 15 act as a whole, to thus make one function feasible. However, the related art portable device 10 must keep the modules 11 to 15 enable performance of authentication processing at all times. For this reason, the short range communication units 12a to 12e of the respective modules 11 to 15 remain operative at all times. The remaining capacity of the respective batteries 11a to 11e implemented in the respective modules 11 to 15 decreases for this reason, which raises a problem of shortening of an operable time (see Non-Patent Document 1).
Non-patent Document 1: IT media, “Vertically separable “Separable portable phone” released by Docomo, [online], Sep. 30, 2008; updated at 17:54, IT media Co., Ltd., [searched on Dec. 10, 2008] on the Internet <URL:http://plusd.itmedia.co.jp/mobile/articles/0809/30/news094.html>